I want to become a full stack developer. I can program and write tests in ruby, I can write applications using Sinatra and now I am learning rails. I bought a book to start learning JavaScript because it's the most popular language and basically will allow me to write modern applications. After I'm done with JS I'll probably jump into something else (rust, go, C, C++, Java, whatever helps do the staff I want).
But watching this video, I'm confused: I avoided CoffeScript because I read in their documentation that in order to debug the code you have to actually know JavaScript so I figured that the best thing to do is learn JS and then use an abstraction (i.e. Coffescript) and tools like AngularJS and Node.js... Is my approach wrong? :-/